Pressure sensitive adhesives containing polydiorganosiloxane polyurea copolymers and a compatible tackifier are well known. They have a variety of applications because they can possess one or more of the following properties: high thermal stability; high oxidative stability; permeability to many gases; low surface energy; low index of refraction; low hydrophilicity; dielectric properties; biocompatibility; and adhesive properties. Examples of such pressure sensitive adhesives are disclosed in U.S. Pat. No. 5,461,134 (Leir et al.), U.S. Pat. No. 5,512,650 (Leir et al.), U.S. Pat. No. 5,475,124 (Mazurek et al.), as well as International Publication Nos. WO 96/30426 (3M Co., St. Paul, Minn.), WO 96/34028 (3M Co.), WO 96/34029 (3M Co.), and WO 98/15602 (3M Co.).
Silicone pressure sensitive adhesives, however, do not typically adhere well to backings such as foam cores or films. The typical challenge faced is that adhesive performance between the adhesive and such backings is generally unsatisfactory.
Thus, what is still needed are adhesives and adhesive articles, particularly tapes such as foam tapes, having adequate adhesion between the adhesive and backing and that provide an effective peel strength and shear strength to a wide variety of materials.